DESCRIPTION (Verbatim from Applicant's Abstract): Many people suffer traumatic spinal cord injuries in the United States every year. Young victims of violent trauma are often left paralyzed because of our inability to limit spinal cord injury following the inciting traumatic event. In addition, many other people suffer spinal cord injury following surgery to correct certain abnormalities of the thoracic aorta. The spinal cord is very sensitive to even brief periods of decreased blood flow. When the thoracic aorta is clamped in order to repair thoracic aortic aneurysms, the spinal cord may suffer from a lack of blood flow. Following spinal cord trauma, blood flow to the injured area of the cord can also be significantly reduced. Lack of blood flow to the spinal cord can result in unrecoverable cord injury and degeneration. We have developed a reliable method of perfusing the spinal cord with cold protective solutions through the veins of the spinal cord, instead of through the arteries (which become blocked during spinal cord trauma or thoracic aortic surgery). This is called retrograde perfusion. Our preliminary studies have shown that retrograde perfusion of the spinal cord with a cold solution can protect the cord during periods of spinal cord ischemia (lack of blood flow). By being able to cool the cord with a cold solution and by being able to supply the cord with nutrients and oxygen, we hope to prevent spinal cord injury during thoracic aortic surgery and to limit the extent of spinal cord dysfunction following mechanical cord trauma. The techniques (rekograde perfusion) and solutions we will be using are very similar to those used to stop and protect the heart during open-heart surgery. In addition, similar retrograde perfusion techniques of the brain have been used to limit neurologic impairment in certain stroke patients. We feel the technique of retrograde spinal cord perfusion with cold protective solutions will become an invaluable therapeutic maneuver for patients undergoing thoracic aortic surgery and for patients suffering spinal cord trauma. Basic research is needed, however, before applying this technique clinically.